Error E00040001

I am using ATI Home Ver. 10, build 4,942 to back up my Dell Latitude D-620. Recently, my scheduled backups began stopping and generating error messages on a few files. The error code is E00040001. I can manually complete the backup by clicking Ignore on the dialog options, but this eliminates my ability to do after hours backup. I have excluded the offending files, but that has not helped.